Solving some DOFs for force and the others for displ.

[Arnaud]

Hi,

We would like to perform a Hybrid Simulation with Opensees where some of the actuators of the experimental element will have to be in Force Control and the remaining in Displacement Control.

For that, we need to be able to solve the equations of motions in Opensees for Forces for some of the DOFs and for Displacement for the other DOFs.
(then, for the DOF solved for forces, the force commands will be applied to the experimental substructure and the corresponding displacement response will be sent back to Opensees, whereas for the DOFs solved for displacement the disp. commands will be applied and the measured restoring forces sent back to Opensees)

Has anything already been done in Opensees to solve some DOFs of a model for force and the others for displacement ?

Do you know some tools that could be useful to help developing such a solver for Opensees ?

Thanks for any information that you could provide me on the topic !

Arnaud